Telephone instrument



J. S. NEWMAN."

TELEPHONE INSTRUMENT.

FILED Aue.16.1915.

Dec. 19, 1922.

NUE/72b!- JOSEPH S.' NEWMAN, OF CLEVELAND, OHIO.

TELEPHONE INSTRUMENT.

Application yfiled. August 16, 1915. Serial No. 45,628.

To all whom t may concern:

Be it known that I, JOSEPH S. NEWMAN, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented a certain new and useful Improvement in Telephone Instruments,of which the following is a full,

clear, and exact description, reference being had to the accompanyingdrawings.

This invention relates to improvements 1n telephonetransmittinginstruments and has particular reference to a unique form ofcarbon cup for use in instruments of this character.

The objects are to provide a very simple and economical, yet highlyefficient, telephone transmitting instrument that is effectiveregardless of the angle at which it is held during use.

I n the attainment of these objects I construct my transmittinginstrument of few,

simple and inexpensive parts that may be conveniently assembled; thecarbon cup comprising a preferably semi-spherical sheet metal shellhaving its open side flared outwardly to provide a shoulder with whichis vengaged the periphery of a disk of mica or the like, and these partsare connected preferably by turning the edge of the cup over the edgeportion of the disk. A screwof standard type, having a substantiallysemi-A spherical head, is extended through an aperture of the disk andclamped thereto by a nut, the head being disposed upon the inner` sideof the disk with its convex surface opposed to the concave surface ofthe cup. Granular conductive material, such as carbon is containedwithin the cup. in suflicient quantity to provide, at all times,regardless of the angle to which the cup is tilted, contact with both@up and screw.

The invention may be broadly defined as consisting of a- .telephonetransmitting in- Y 4strume'nt comprising a diaphragm having connected toit a. pairlof opposed electrodes between which. is disposed aquanti'tyof granular conductive material, one of said electrodes havinga convex surface in opposed relation to a concave surface of the other,the quantity of carbonwithin the Ispace between said surfaces being suchthat it is in constant contact with both.

In the accompanying drawing which forms 'a part hereof, and whereinsimilar reference characters designate corresponding parts throughoutthe several views, Fig. 1 is a central vertical section through atransmittlng lnstrument constructed in accordance with my invention; Fig. 2 is a perspective of the elements of the carbon cup, separated; andFig. 3 isan enlarged sectional view through the carbon cup, showing thesame assembled.

The transmitting instrument A comprises a base 1 which is preferablyformed of a circular block of wood having a central aperture'2 for thereception of a tenon 3 that 1s formed on the lower end of the stem 4 ofthe instrument. This stem is also preferably made of wood and is formedwith a bead 5 at its lower end, and an enlarged upper end 6 that issubstantially frusto-conical in shape, thereby to render the stem ofartistic design. It will be understood that the shape of the stem willallow it to be readily formed at aslight expense upon a wood turninglathe. i cup-shaped shell 8 has a hole 9 that is applied to a projection10 rising from the stem 4. The forward or open side of the shell 8 isclosed by a cap 11, and bef tween a shoulder 12 thereof and the forwardedge of the shell, is clamped the periphery of the metallic diaphragm13, the ca 11 havlng a flange 14 which Overlies the ront of the shell. Afunnel shaped mouth-piece 15, having a reduced inner end 16, is appliedto the cap 11 by having such reduced end lfitted into an aperture 17 ofthe cap. The mouth-piece has a central openin 18 so that the sound wavesintroduced into the mouth-piece may have easy access to the diaphragm..Thls shell, the cap which closes the forward side thereof, and themouthpiece 15 are preferably made of wood., and may be permanentlysecured together by gluing the engaging portions thereof. In likemanner, the shell 8 may be secured to the stem 4, and the stem 4 to thebase l.

`A carbon cup 20 is located within the shell 8 and is connected to thecentralportion of the diaphra m 13. The cup 20 is pressed from a sing epiece of metal and is semi-spherical in shape, the wall of the cup beingflared outward at its open vside to form a shoulder; 21 against whichthe periphery of a disk 22, preferably of mica, may be securely held bycrimping the edgel23 of the cup over the exposed surface of the disk, asclearly shown in Fig. 3.Y This Aim and a screw 26 is clamped to the disk22 through an aperture in the disk for the application of a nut 27,between which and the head of the screw, the disk is securely clamped.The screw is then passed through an aperture in the center of thediaphragm 13, and it has applied to its protruding end, a second nut 27.Extending through one side of the shell 8 `are two binding posts 28 and29, the former of which `has connection, through the wire 30, with themetallic cup 20, While the binding post 29 is connected, through thewire 31, with the metallic diaphragm 13. The outer ends of these bindingposts have the Wires E attached to them. It will be observed that theonly electrical connection between the diaphragm and the metallic cup isthrough the particles of the granular carbon 25.

`Following the well knownv principle of transmitting instruments, whenthe diaphragm 13 is vibrated, the granular carbon in the cup 20 isagitated to vibrate or. fluctuate the current which passes therethrough.

Having thus described my invention, what I claim is 1. A device of thecharacter set forth v'comprising a one piece metallic semi-sphericalshell having its open side flared out` wardly to form a shoulder, a diskof inquantity to be in contact at all times withVl the shell and screwhead regardless of the angular position'of the device.4

2. A transmitter comprising an open sided shell, a quantity of granularmaterial. within the shell, and a plate extending across the open sideof and supported solely by the shelll and serving to retain the granularmaterial within the shell, the shell and plate bein connected togetherby having the edge o one crimped about the edge of the other. l 3. Atelephone transmitter comprising a diaphragm and a pair of electrodesconnected to and supported solely by the diaphragm, and granularconducting material between the electrodes, the electrodes having curvedsurfaces, vand the convex surface of one electrode lying opposite to theconcave portion of the other electrode for the purpose specified.

4. A telephone transmitter comprising, in combination, a diaphragm, apair of electrodes connected to and supported solely the diaphragm, andgranular conducting material between theV e ectrodes, the electrodesbeing formed on complementary curved surfaces, for the purposespecified.

6. A telephone transmitter comprising a diaphragm and a pair of freelysuspended and independently vibratory electrodes in conjunctiontherewith, connection from the A 1 diaphragm to said electrodes,l andgranular .conducting material between the electrodes, the electrodeshaving curved surfaces, and the convex surface of one electrode lyingopposite the concave portion of the other electrode for the purposespecified.

7. A telephone transmitter comprising, in combination, a diaphragm, apair of freely suspended and independently vibratory electrodesconnected thereto, and granular conductingmaterial between theelectrodes, said electrodes being formed on complementary curvedsurfaces, for the purpose specified.

8. A transmitter attachment comprising an inner curved electrodeprovided with elements for engaging the transmitter, a thinvibratoryinslating disc carried by said electrode, an outer curvedelectrode projecting from the periphery of said disc, said outerelectrode surrounding the inner electrode and uniformly'spaced from thelatter, said electrodes and thesaid disc combining to form a freelysuspended structure having an enclosed curved chamber, and carbongranules deposited within said chamber for maintaining contact betweenthe opposed surfaces of the said electrodes.`

In testimony whereof, I hereunto afiix my signature.

JOSEPH S.' NEWMAN.

